For me, 1. For the exercise. 2. Just to see how good i can be and the endless journey of trying to improve in every aspect of the game. 3. The problem solving part on how to beat an opponent. 4. The challenge of trying to stay relax while playing knowing that the more relax you are the better you will play. 5. Trying to dress nice for the court, what with all the fashion statement we see on the professional tour now.